What bad intentions could Deathstroke, the Sorcerer Supreme devoted to protecting humanity, possibly have? He was simply doing it for Peter's own good.
Put a stunning beauty aboard his ship, and a teenage boy's hormones would keep him thinking about her alluring figure. Once he knew she was on board, he definitely would not refuse certain things.
But as a proper Superhero, Peter would absolutely never touch a woman in that profession. In his view, it was exploitation—using money as bait to force women into making certain choices. That was wrong.
But she was an Alien, so human moral standards could not be applied to her. Besides, in the cosmos, a companion was genuinely a highly prestigious profession, like a hireable courtesan. Many Captains who had spent their entire lives sailing the stars were less respected than they were.
In any case, once Adjutant reported that Peter had encountered such an opportunity, Su Ming directly ordered that the beauty be put aboard his ship as training for Little Bug.
Peter would most likely end up caught between his physical instincts and his mental aversion, gradually strengthening his willpower through the agony of wanting to eat but being unable to.
Peter of 40K Earth was far stronger than his Otherworld Variant in the MCU. Especially since he still had a Symbiote Deathstroke had given him, though it seemed he had named it Red or Little White?
That Symbiote still seemed to be dormant, and it had been fairly docile before. But to become a qualified Symbiote host, powerful willpower was indispensable. Between host and Symbiote, the human who knew how to restrain desire had to take the lead. Otherwise, if the Symbiote controlled their actions and unleashed its appetite without restraint, the host would eventually become a murderous maniac like Carnage