The whole idea of connecting the washer drain hose to the standpipe is wrong. This is supposed to be a air gap drain. In other words, the hook end on the washer hose is meant to be hung in the open end of the drain pipe. Probably the biggest problem is the drain pipe is way too small. You said it was 1-1/4", but I see 1-1/2" on the pipe. However, today's washers dump water so fast that it requires a 2" standpipe into at least a 2" drain (larger would be better. I can not tell of sure, but I think the rest of the visible drain is 1-1/2" as well. Also, I don't see a vent in the drain between the P trap and where it enters the wall. So there are 3 issues that need to be dealt with. No duct tape needed, just some proper plumbing.