Titillation

[Sonia]

The act of tickling, or the state of being tickled; a
tickling sensation.

[Justin Bieber]

n., Excitement, usually Sexual or romantic, causing a hard on of [the pecker] and/or clit and nipples, but it may occur with other forms of thrill-seeking, such as extreme sports, extreme amusement park rides, or [space monkey].
The occurrence of tit as the first syllable of titillation is purely coincidental.
v. form, [titillate].

[Mark Zuckerberg]

The arousal of interest or excitement, especially through sexually suggestive images or words.

[Julene]

[Vibration] of the [mammaries], usually during jogging or [physical activity].