Aftercare and popping out - terms I have not heard before

So apparently 'aftercare' relates to sex or something related to medical and/or traumatic experiences. I don't know what it is. To me sex is a traumatic experience. Perhaps there's correlation.

Apparently 'popping out' refers to a woman's boobs on amusement park, etc. rides. I've never had much to do with women's boobs to know about this. Do women's boobs tend to 'pop out' in other situations?

Anyone got alternative meanings that stack up?