How to stop elderly dad from peeling in the corner of the bathroom instead of the toilet?

My dad is excessively overweight. His belly hangs out and over his area and he’s not able to reach his area to aim either because it’s armed or super short. He walks up to the toilet but then just stand there and it always pees all over the wall floor the toilet everywhere. I try talking to him about it and he gets mad at me and refuses to even talk to me about it. I am at my wits end with it, any suggestion? Or miracle ideas?