Everything is good if it is tasteful and if it is time for that. Tasteful and emotional scene wouldn't spoil anything especially if the plot was logically driven. But porn would.
Of course, there will always be people, whinning: "Noooo, why sex there, this is disgusting!" And there will be people whinning: "Whyyyy there still was no sex?!"
Moreover, people usually react negatively to sexual scenes with "wrong" characters. Like there's a couple, but of the partners cheated and you drew that in details. I once did something like this and my readers were furious, and even some haters have come calling me disgusting. However, that was one page only and I was expecting such reaction and trolled my readers on purpose.
But as for sexual scene between a couple - people tend to like that. Shippers are crazy sometimes I currently have one forming couple in my comics and my readers often shout they want them to have sex or kiss at least. I keep trolling and teasing, I'm a bad author XD
Anyway, you are the author, you know what better suits your story and you make the choice what to show and when. Respect and care for your readers are great, but still the final decision is yours only.
I personally prefer to keep my comics R rated. There are only bits of sexual scenes, like sensitive touches, kisses, moans, etc. Most of the time they're needed for the plot, because some important words were told during such scenes, or something has happened. Or such scene will be remembered later to say something. But no actual porn. However, I'm not scared to draw more explicit scenes, but they are additional and I publish them on Patreon or other special sites (if they're free to read). I guess this is the best way for me to keep the story whole and make fan service available only for those who want it.
I guess if you're scared, you may try to move slowly, like showing kisses first, then try more sensitive touches and watch your reader's reaction. Or try to publish some NSFW content on another platform and give the link to your readers and watch reaction again. And finally just ask your readers to comment if they would like to see a sexual scene. Maybe that will help you to take the final decision