These emojis have triangles for mouths. These triangles fill these happy emojis with smiles, as if they can’t open their mouths.

Triangle Mouths
( ´ ▽ ` )ノ(^▽^)(´∇ノ`*)ノ
(ノ^∇^)⊂((・▽・))⊃( ^∇^)
( ゚▽゚)/(‐^▽^‐)(“⌒∇⌒”)
´▽`(*^▽^)/(^▽^)
(*~▽~)(*≧▽≦)(⌒∇⌒)
(⌒▽⌒)θ~♪(/^▽^)/(^∇^)
(^▽^)( ̄▽ ̄)ノ( ̄▽+ ̄*)
(゜▽゜;)(=´∇`=)(=⌒▽⌒=)
(≡^∇^≡)(≧∇≦)/(⌒▽⌒)
(⌒▽⌒)☆(⌒▽⌒ゞ(●⌒∇⌒●)
(❁´▽`❁)✲゚(ノ゜▽゜)°˖✧◝(⁰▿⁰)◜✧˖°
~ヾ(^∇^)∩(︶▽︶)∩≧(´▽`)≦
ー( ´ ▽ ` )ノヾ(´▽`;)ゝヾ(^∇^)
d=(´▽`)=bo(〃^▽^〃)oo(^▽^)o
O(≧∇≦)Oo(≧∇≦o)(๑꒪▿꒪)*
(⁎⚈᷀᷁▿⚈᷀᷁⁎)(≧∇≦*)(=^▽^=)
o(^▽^)o೭੧(❛▿❛✿)੭೨☜(⌒▽⌒)☞
☜(˚▽˚)☞ɾ⚈▿⚈ɹヘ(= ̄∇ ̄)ノ
φ(*⌒▽⌒)ノ(・▽・)(☆▽☆)
≡(*′▽`)っ」( ̄▽ ̄」)(〃⌒∇⌒)
〔´∇`〕(゜▼゜*)໒( ͡ᵔ ▾ ͡ᵔ )७