YES. What /u/El_Cid_Vicious said. Work on your insecurities and boost your own confidence - it definitely can't hurt, and it anything, it will help.

Also, I would recommend getting to know the girl better, being friendly to her, and showing your husband you are on board and happy for him. He will be thrilled to share his excitement WITH you and see you taking an interest in what's important to him. He will also tell you what's going on more and be less secretive because he won't have to worry you will be jealous, mad, etc. (or potentially sabotage your marriage or his new business opportunity).

You would feel much more secure by knowing her and knowing more about what's going on, plus you wouldn't have to feel so left out - and I think ANYONE would feel jealous and left out in a situation where their SO is excitedly sharing something exclusively with someone else, especially when that "something" is very important to the SO and that "someone" is extremely attractive. Sure, the phone snooping was not something you are proud of and you will have to live with that, but I think your feelings are totally normal.

Even if you can't bring yourself to truly like her that much, you should still give her a chance because it's the right thing to do as long as your husband is important to you and no one has done anything wrong. Plus, the more you are close with the girl and know her personally, the harder it would make it for her to potentially make a move on your husband at some point. It's harder for people to betray someone who is a friend or a person they like than it is to sleep with a married guy whose wife they don't know well. I'm pretty sure it's even easier when the married person complains about his/her spouse - they might even see it as doing him/her a favor by ruining the marriage.

I'm not at all suggesting your husband complains about you to her or is likely to cheat - plus it takes 2 to want it for the cheating to even happen - I'm just saying that being on board with everything is the most preventative thing you can do anyway. It would strengthen your relationship with your husband AND make it harder for the girl to do anything with him that would make you uncomfortable, so it's somewhat preventative on both ends (and also just makes the whole thing feel better for everyone involved).

Also, starting a business with someone you are interested in pursuing romantically is a horrible idea - sometimes, even platonic best friends can't make that shit work - so the fact that they are pursuing a business thing in the first place is basically proof that they have no interest in getting together (assuming they're not idiots), so I really don't think you have any reason to worry.

Well, that was longer than I planned, but if you've even read this far, good luck with everything! (