Speed and Viagra - sounds good but not safe?

[Flat4]

Mr & Mrs SWIM love speed (UK rubbish) and sex. Sadly Mr SWIM is one of the few that finds too much causes Mini Mr SWIM to go on strike. SWIM said hes read up on possible dangers of speed and viagra but was wondering that considering the stuff obtained in the UK is low in quality and potency, taking a small amount with say half a viagra each, should be a reasonably safe thing to do. Just a little of each and see how things go over a few hours? All opinions appreciated.