No, Sue Lyon was only 14 when cast and filmed. She was still only 15 when it premiered. The novel specifies Lolita’s age as 12(!) at the beginning (when she seduces Humbert). The studio wanted to say the film character was supposed to be older (like 16 or 17) but Kubrick got them to settle on simply not specifying. However the fact that Lyon was only 14 was kept quiet (she looked older). And I would say that the sex scene was more than ‘hinted at’. It was (just barely) indirectly implied as strongly as the time would allow (for sex scenes in general, not just between a young girl and an older man). The 1997 remake went further, but only a little (no nudity). It included Dominique Swain undoing the fly on Jeremy Irons’ pajamas.