How long should a roommates' significant other stay over?

So my friend and roommate of two years recently started dating a guy (long distance) who works for an airline, so he can visit whenever he gets standby. Lately, he's been staying over every other week, in 3-4 day stretches. This has been going on consistently for about 3 months. And she mentioned him coming over next week after he just left on Sunday...

I work from home, and having a third person around constantly is really disrupting my routine and space. Normally, our living situation works because my roommate goes into the office three days a week, but when her boyfriend's here, she decides to work from home too. Which is exhausting for my sometimes very introverted self in a small space. I need space to recharge, and so our living arrangement has always worked for me until recently.

I want to be supportive, but this situation is starting to get on my nerves. Should I talk to my roommate about it or am I overreacting since this is a brand new relationship?

I personally think even 2 days can be pushing it. I've always respected our space and never had my boyfriend over longer than that.