diff --git a/lib/connector/meshcore_connector.dart b/lib/connector/meshcore_connector.dart
index 4289d8b..f8f0018 100644
--- a/lib/connector/meshcore_connector.dart
+++ b/lib/connector/meshcore_connector.dart
@@ -6546,10 +6546,16 @@ class MeshCoreConnector extends ChangeNotifier {
         _parsePocketMeshReaction(message.text, isDm: true) ??
         _parsePocketMeshReaction(message.text, isDm: false);
     if (reactionInfo != null) {
-      // Check if we've already processed this exact reaction
+      // Check if we've already processed this exact reaction. A room server is
+      // many-party over the 1:1 transport, so the reacting author belongs in
+      // the key or two members sending the same emoji collapse into one; in a
+      // true 1:1 the author prefix is empty and the key is unchanged.
       _processedContactReactions.putIfAbsent(pubKeyHex, () => {});
+      final reactingAuthor = message.fourByteRoomContactKey
+          .map((b) => b.toRadixString(16).padLeft(2, '0'))
+          .join();
       final reactionIdentifier =
-          '${reactionInfo.targetHash}_${reactionInfo.emoji}';
+          '${reactionInfo.targetHash}_${reactionInfo.emoji}_$reactingAuthor';
 
       final isDuplicate = _processedContactReactions[pubKeyHex]!.contains(
         reactionIdentifier,
diff --git a/lib/helpers/pocketmesh_reaction.dart b/lib/helpers/pocketmesh_reaction.dart
index 234dcae..d8b3da1 100644
--- a/lib/helpers/pocketmesh_reaction.dart
+++ b/lib/helpers/pocketmesh_reaction.dart
@@ -87,7 +87,7 @@ class PocketMeshReaction {
     required String? sender,
     required String hash,
   }) {
-    if (emoji.isEmpty || !_startsWithEmoji(emoji)) return null;
+    if (!_isReactionEmoji(emoji)) return null;
     return PocketMeshReaction(
       emoji: emoji,
       targetSenderName: sender,
@@ -95,23 +95,35 @@ class PocketMeshReaction {
     );
   }
 
+  /// A reaction is one emoji, possibly with a variation selector, a skin-tone
+  /// modifier or ZWJ joins. Eight runes is well clear of the longest such
+  /// sequence and nowhere near a sentence.
+  ///
+  /// This cap is the guard that matters: without it, any multi-line message
+  /// starting with a symbol and ending in eight Crockford characters would be
+  /// swallowed whole and shown as the reaction "emoji".
+  static const int _maxEmojiRunes = 8;
+
   /// Deliberately conservative: a missed emoji only means the reaction renders
   /// as text, which is the behaviour we have today, while a false positive
   /// would swallow a real message.
+  ///
+  /// Arrows (U+2190-U+21FF, U+2934-U+2935) are excluded on purpose even though
+  /// they carry the Unicode Emoji property. They are ordinary punctuation in
+  /// prose, and a live capture from this mesh contained U+2192 mid-sentence in
+  /// a normal channel message.
   static const List<List<int>> _emojiRanges = [
     [0x1F000, 0x1FAFF],
     [0x2600, 0x27BF],
     [0x2B00, 0x2BFF],
-    [0x2190, 0x21FF],
-    [0x2934, 0x2935],
     [0x3030, 0x3030],
     [0x303D, 0x303D],
     [0x3297, 0x3299],
   ];
 
-  static bool _startsWithEmoji(String text) {
+  static bool _isReactionEmoji(String text) {
     final runes = text.runes;
-    if (runes.isEmpty) return false;
+    if (runes.isEmpty || runes.length > _maxEmojiRunes) return false;
     final first = runes.first;
     for (final range in _emojiRanges) {
       if (first >= range[0] && first <= range[1]) return true;
diff --git a/test/helpers/pocketmesh_reaction_test.dart b/test/helpers/pocketmesh_reaction_test.dart
index b3ab7d8..5d6efd3 100644
--- a/test/helpers/pocketmesh_reaction_test.dart
+++ b/test/helpers/pocketmesh_reaction_test.dart
@@ -142,6 +142,50 @@ void main() {
         expect(PocketMeshReaction.parse('\ndyps6yf0', isDm: true), isNull);
       });
 
+      test('a sentence starting with an arrow is not a reaction', () {
+        // Arrows carry the Unicode Emoji property but are ordinary punctuation.
+        // A live capture from this mesh had U+2192 mid-sentence in a normal
+        // channel message, so the range is excluded outright.
+        expect(
+          PocketMeshReaction.parse(
+            '\u{2190} Turn left at the fork\ndyps6yf0',
+            isDm: true,
+          ),
+          isNull,
+        );
+        expect(
+          PocketMeshReaction.parse('\u{2192}\ndyps6yf0', isDm: true),
+          isNull,
+        );
+      });
+
+      test('a long run of text after a real emoji is not a reaction', () {
+        // The swallow risk the rune cap exists for: without it the whole body
+        // would become the reaction "emoji".
+        expect(
+          PocketMeshReaction.parse(
+            '\u{1F44D} thanks, that fixed it for me\ndyps6yf0',
+            isDm: true,
+          ),
+          isNull,
+        );
+      });
+
+      test('accepts a multi-rune emoji sequence', () {
+        // Skin tone modifier, then a ZWJ family sequence.
+        expect(
+          PocketMeshReaction.parse('\u{1F44D}\u{1F3FD}\ndyps6yf0', isDm: true),
+          isNotNull,
+        );
+        expect(
+          PocketMeshReaction.parse(
+            '\u{1F468}\u{200D}\u{1F469}\u{200D}\u{1F467}\ndyps6yf0',
+            isDm: true,
+          ),
+          isNotNull,
+        );
+      });
+
       test('the leading character is not an emoji', () {
         // The realistic false positive: a two-line message whose last line
         // happens to be eight Crockford characters.