Brutus,
Ask your girlfriend to explain to you about the Theocratic Strategy that was mentioned just above. In short, this "strategy" tells her that it is OK to lie in the defense of God's True Organization.
You're going to MARRY this chick?
Good Luck, dude!
Do you know which sexual practices the Watchtower approves for married couples? You may as well invite an elder to come with you on your wedding night to make sure the consumation is performed in accordance with Watchtower guidelines.
"And who are these Watchtower Elders who will be directing each stroke on my wedding night?" you ask.
You'll be pleased to know that according to the Watchtower itself, these men are "untrained amatuers." They have no theology degrees, no psychology degrees, no training that might provide them with leadership skills of any sort. They just read the Watchtower and that makes them qualified to tell someone else how to run their life and to sit in judgement of anyone who breaks the man-made rules.
Do you plan to have kids? Think about what you might like your kids to be like, what you might like to see them accomplish under your benevolent parenting; write those things down, then wad them up and throw them in the crapper, because they will NEVER come true! Say goodbye to your kids the day they're born, because they'll be raised as Jehovah's Witnesses no matter what YOU think about it. Your (oops, I mean HER) kids won't be permitted to engage in school sports activities or social activities, and they'll be discouraged from academic excellence as well. They WILL, however, become trained magazine salesmen of the Watchtower. You're just a sperm donor, Jehovah of the Watchtower is their Father.
..and pray to whatever you hold Holy that your kids never fall victim to sexual abuse while under the "care" of these Watchtower shepherds, because the Watchtower turns a blind eye to such conduct, refusing to report child sexual abuse to the police.
When you get tired of having this weary, joyless, angry old bible-thumping millstone around your neck, wondering what became of the beautiful girl you fell in love with, you'll discover the difficulty of getting her to give you a divorce.
You're in for a real TREAT, Brutus!