You don't necessarily have to be overwhelmed/have adverse things going on in your personal life to justify a hiatus. Sometimes we all just plain burn out, lose interest, lose our motivation to write, etc. It's best to really be honest, don't worry about fabricating some sort of outside issue if one doesn't exist. If you force yourself to write through a burnout just because you feel like you [i]have[/i] to have some kind of better excuse to justify taking a break, your writing is going to suck, your partner will notice, and your rp will suffer. Not good for anybody. Your partner should understand, it happens to all of us. 

I've taken breaks from the guild in the past that lasted almost a year, and shorter ones for a few months, but you really don't know how long it'll take to get your energy back until it happens. When you're ready to return and craving rp again, return. Don't force yourself to come back after a certain time if you're not feeling it.