UKH

I'm there with a non-climbing friend and can climb several of the days, flexible as to which.

Hey Robin, definitely join the facebook group "Tenerife Climbing Scene". Pretty active and loads of people tend to look/find partners there for all grades. 

I'd say April/May is low season for climbing visitors, so it may not be as active as Dec to Feb, but worth a try.

If you need any insights, give me a shout.

I'll likely be in Tenerife for this time. I don't have social media to join these groups but I've heard the climbing hostel is a good way of doing this.