Typical problem. People dont learn till they get the lesson.
How many times have we spoken of regulated masturbation? 1000s, still people dont listen.
Masturbation is an enjoying act, should be done with lube, slow and soft touch. But guys of your age and below cant help torturing the little one. Once that gets a problem, they find, why didnot I listen before?
Penis bend doesnt happen by masturbation, unless you give too much pressure unequally. And when it happens, accept that. You can have a normal sex life, but the bend one wont get straight again, still there wont be a problem in future.
Those who are having a fun time and torturing their little one, please do it proper way.