Morus species I believe. Personally I would dig it out.

Here are some pictures of some black raspberries for comparison (unknown species, but our neighbors say they're blackcaps). I just ate the pictured cluster (our neighbors said we could eat those on our side of the fence). I love them. The fruit ripens in June or July here in SW Idaho (not everbearing).

It is a native passionflower commonly referred to by some locals as maypops or as purple passionflower. Passiflora incarnata. Native in more northern and eastern parts of the state. I'm not sure how well it does in western OK and southcentral through southwestern OK. I'm in southcentral OK and never have seen it growing in the wild here, but people do plant it in improved soil and keep it happy with irrigation in our hot, dry summers down here.

I have a couple of questions for you, without which we may not be able to guess the answer: Where are you? State, nearest big city, zone, if you know it. Is the vine growing in sun or shade? How big is the flower? (As big as a quarter? A dime?) How big is the fruit? Is it climbing into the trees or bushes, or is it along the ground?