My girlfriend [21F] of 18 months asked my [22M] preference regarding the use of a penis ring and I don't know what to do

Please let me know if there's any other relevant details that I forget to provide.<br><br>We've been a official couple for almost 18 months now, and we've had sex over 30 times. We don't use condoms for personal hygiene reasons, so we use a semen-friendly lubricant with spermicide removed and a condom wrapper on top. <br><br>She's always been very open to sexting about fetishes, kinks, fantasies, etc., but I'm generally not too into it. Yesterday she texted me "Do you have a penis ring preference, small, standard or large? I want to buy you one for Christmas". I replied "I didn't know those were a thing, are they for pleasure or safety?" She replied "Both! They come in different sizes, but most guys like standard. If you have one, I can take it to the store to make sure I get the right size". I asked one of my friends and he said he has a small one, but he's smaller than the average guy. <br><br>So yeah idk what to do. I want to satisfy her and make her happy for Christmas. Is it rude to lie and say small? If so, how should I respond? If not, what should I do? Please provide personal anecdotes if you've had a similar situation.