Thanks for the replies!
Yes, I think "good" sex is the best option. We keep talking about scenarios where she would go with another man and at least she is comfortable with the whole idea.
Last weekend we went to a party and she flirted quite a lot with a friend of mine she had just met. They talked very close to each other, they were holding hands and there were the obvious physical contacts (e.g. her hands on his arms, his hands on her waist and so on).
Towards the end of the party, and with the level of holy water increased,
his hands were on her ass more than an average husband would tolerate.
I was there, instead, looking at them with a huge erection, knowing that my quite surprised friends were seeing the same thing!
After the party, on our way home, I asked if she liked flirting with him and she said that she behaves with other men as if she is single, whether I am there or not. She just stops before kissing, "For the moment", she added
This weekend will be out (abroad) on a business trip with the whole department where she works. 3 nights out. I hope she gets the flirting going and at least cross the "kissing barrier"!
I'll be here masturbating at the idea