Allstar, each person will deal with it differently. Some monos might feel jealous when their wife comes home "from a hot date, wet and ready to go." Others might feel turned on to have her in such a state, and happy to make the most of it.
Kind of like with say, her going to see a rom com with her gfs, getting turned on and then coming to you. Or reading some erotica, or seeing something else sexual. Or it being her ovulation time and she's ready to fuck anything that moves...
All her desire will not come directly from you. Other things, and people, will turn her on. There are hot sexy desirable people all over the place.
I get the idea you are feeling in a desperate hurry to get this all figured out before you deploy. You may have pressured her into letting you call her "girlfriend" (after only 4 months, and with her already having another lover), and wanting some sense of security she'll still be there for you when you get back.
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
me: Mags, 59, living with:
miss pixi, 37