It can take up to 12 years for pluto to transit a house. So you're gonna be feeling Pluto's effect for a long, long time.
This starts with Pluto making a conjunction with your Ascendant (see Pluto Transits in Aspect to Your Natal Ascendant) , but the effect can last for years. Usually, you will become more assertive. This is the “Nobody better mess with me” transit. It also can bring suppressed feelings and desires up to the surface, things that you don’t want to face. Some tend to become more domineering with Pluto. Others try to suppress this, but find instead that they seem to attract people who try to push them around.
I'd suggest you look at your transits, progressions and solar return. I was in a similar situation a few months ago, and I found my solar return to be very telling when it comes to that kind of extra-curricular activities.
Look at where the Moon is located. Moon/Venus in the 12th house is your typical affair placement. It would also be good to look at the 5th house. Years with an active 5th house often bring increased romantic activity. I'm sure we can help you pinpoint what really is going on if you posted your transits, progressions and solar return. A horary query wouldn't hurt either.
Good luck, and keep us posted.