Ohhh, doesn't she know the main use for a metamour is to sit around and bitch about the shared lover?
But seriously, dude, you and your wife have issues. If she was neglected when you were busy with school, now is the time for more togetherness and FUN together to reconnect. "Marriage in trouble, add more people" is a mistake in poly.
Now is not the time to shower love and attention on your gf while your wife sits in the corner and beats her breast for succumbing to NRE without your approval. Where do you expect to be a year from now? 5 years?
It could be a good time for some rekindling of your former romantic feelings FOR EACH OTHER. Do you date? Make love frequently? Give each other little gifts? Sit and cuddle with a beverage and some music playing with candles lit? Take walks, go on day trips?
Being poly means loving more than one. Maybe it's time to love your wife up (instead of just the gf), understand she was in a desperate position (to have had sex with your hated cousin, she must have been really desperate). If it takes therapy, go for it!
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags (poly, F, 60) loving miss pixi (poly, F, 38) since January 2009, living together since 2013
also loving Punk (monogamish, 42, M) since Oct 2015
"Master," (mono, 34), miss pixi's Dom for 2 years