well i used to hang out with my girlfriend all the time. we did this for two years or so until she recently broke up with mei regret not doing more stuff with my friends, i lost quite a few of them and am struggling to get back in tight with them. i enjoyed every minute with my gf but i should have balanced it better because now it hasn't worked out so well....
I went through 2 relationships that both lasted 2.5 years each, and during both we spent every second of spare time together. No good.
I am currently single, and obviously loving it, but when I do find someone next I think I'll take a little more time for myself/friends/family.