I believe a kiss so intimate as the sex. Therefore, in such moments, probably also feel embarrassed, but sometimes you can kiss, just no tongue, so it never came to vulgarity and debauchery. Here are many not ashamed even in the streets kissing in public now, probably just such people and not shy to kiss in front of their parents. Everyone has an opinion on this question, but I believe that in this respect we need to behave modestly and kiss only when you are with your partner alone. kiss should be the same as sacrament and sex.