How about we put away the games people seem to use to complicate things. You’re both older and mature individuals and I’m sure both have been around the block a couple times. He doesn’t need to know your history.
Just be flat out honest with him. Sit outside with a glass of wine. Sooner or later he will see ya and probably walk over with a beer to say hello. Then just tell him “ Look, I find you immensely attractive. If you are not attached and would be interested in a Blow Job right now, why don’t you come inside. If now doesn’t work, just let me know”. Then just leave it at that. If he’s interested, I’m sure he will knock on your door. If he doesn’t, then you have your answer and you move on. At his age, I doubt he’s all of a sudden going to invite all his friends lol ber so he can point you out.
Stop beating that bush. Firm and direct I always say. The worst thing s the word No. and I’ve not heard of anyone dying on the spot hearing that 2 letter word