Flutter

[Justin Bieber]

To vibrate or move quickly; as, a bird flutters its
wings.

[Lizzy Liz]

[British] term for [placing] a [bet] on something.

[Vania]

[basically] [means] [blushing]

[Sonia]

a [large] [group] of [butterflies]

[Renato]

(of a bird or other winged creature) fly unsteadily or hover by flapping the wings quickly and lightly.

[Couch Potatoe]

A word describing someone who is not quite [a crush], but whom you are still interested in getting to know. I.e. that [hot guy] you always see in [the hall] at school, but you dont know his name or what hes like.

[Raeanne Dimick]

The [slapping] of the male testicles against [the womans] pleasure [zone] during sexual intercourse.

In other words when youre having sex and the guys balls slap against the woman