I think you can’t have it both ways.
The best thing to do would be to NOT accept the offer yet. Tell the buyer that you have more viewings booked and after they have viewed and perhaps offered you will decide on his offer.
The trouble is you already accepted.
The question becomes, if after the weekend, other people express interest,e Feb though you’ve accepted his offer, will you consider others. Are you a reliable seller?
As the buyer, I would be wary of dealing with someone who after accepting an offer wanted to show other people it. The only motive can be to get a higher offer…which means as buyer you lose the property.
If you want a price war - say so. That means no offer is yet accepted. But don’t accept and then continue letting people look.
And be clear in your own mind that once you accept an offer, you should proceed. Tell the buyer that you will require proof of funds, solicitor details etc to the EA on Monday and that you expect them to proceed swiftly. If they can do this, then if you accept their offer, you should honour it snd take the house off the market. You have to be decent at the point you accept the offer.
Your mistake has been accepting before you’ve been ready. That was unfair.