"Bent on pleasure" is a phrase that refers to someone who is determined to enjoy themselves at all costs. If you're looking for synonyms to use in place of this phrase, there are several options to consider. You might describe someone as being "fixated on fun," "obsessed with enjoyment," or "single-mindedly pursuing pleasure." Other options include "determined to have a good time," "hell-bent on having fun," or "intent on indulgence." Regardless of which synonym you choose, using expressive language will help convey the sense of someone who is determined to live life to the fullest.