ironic that getting into a relationship dynamic that is mainly focused around "multiple partners" leaves with you with less time with your partner(s) at times...hahaha. Just a strange observation. Do you guys talk alot? I'm like, what alot other the above people mentioned, a private person who can be very social. If I were you, as long as I was txting him or calling him everyday/every other day i'd be kewl. Just fill up the time with other stuff
Something that I did earlier in a previous relationship helped. Me and my g/f made an agreement to write detailed emails sometime before we went to sleep. Writing, even if you aren't a "writer", seems to bring up some deep and truthful thoughts when writing to a loved one, you'd be surprised. Anyway, just a suggestion.