I have that stuff all the time.
In my low-magic campaign that has seen maybe 6-8 sessions, two pcs have indeed 'gotten it on', even though one of 'em is a closet homosexual knight who yearns for his brothers in arms.
An arranged marriage and demands for an heir can go a long way.
I also have, in the same game, one pc who is constantly coming on to another (who is, hmmm, only very slightly responsive- and only when he says or writes passionate things in elven).
I've found that romance is hard to encourage in-character, but there are ways- the arranged marriage, philtres of love, etc. The best advice I have, though, is
know your group. Some people really enjoy this aspect of roleplaying; some get creeped out. Some are only okay with it if the
players involved are opposite gender; some don't even care if the
characters are opposite gender.
