This all depends on if you are friends and have sex (Friends with Benefits) or if you guys are just having sex (F_ck buddies).
Sexual addict
It could be a chronophile (one who is obsessed about time).
meterologist
meterologist
Lycanmaniac --------------------------------------------------------------------------------------------------------- Lycanophile??
Workohalic or social
an astro nut!
skull collector
You !
Party pooper?
vamp freaks
sociopath
crazy cat person