Depends on whom i'm tickling and whom i'm having sex with. I don't like having sex with women i'm not attracted to. I can tickle a woman that has a fun disposition though regradless of whether or not i'm attracted.
If it's a girl i'm dating.....then it'd be sex ;o)
A platonic girlfriend....tickling ;o)
ahhh....I do love my life ;o)
GQ