Just came across 「チューした」 in a Japanese TV programme (OK, I admit it was Terrace House ?). Had to look it up because it seemed a bit strange - it means "we kissed" (said by a girl/young woman, I think men would not normally use it).
The reason I found it strange is that the katakana チュー sounds like "chew", which doesn't seem very romantic ?. But apparently it's onomatopoeic, referring to the sound of kissing, rather than chew.