Your wife is beautiful! You are so lucky for her to have a boyfriend. What a joy that is. I would love more pics of her tits, they are gorgeous!
Don't worry about what is uncomfortable - if it's uncomfortable, don't do it. Take it at your speed and in your own way. A lot of people come her, share their experience, their fantasies, read others', and even project their fantasies on others. It's part of the fun but surely don't feel obligated or pressured into ever doing anything you don't feel perfect. There are no rules, there are no benchmarks you have to meet. Just enjoy it!
And thanks for sharing your wife with us, too, I'm enjoying it a lot!