An occasional drink with a normal dose of ibuprofen is usually fine, but alcohol raises the risk of stomach irritation and bleeding, so go easy and ask your pharmacist if you drink regularly.
Ibuprofen is an NSAID, a class of painkiller that can irritate the stomach lining and cause ulcers or bleeding, sometimes without warning. The NHS says you can eat and drink normally while taking ibuprofen but to "try to avoid drinking a lot of alcohol because this can increase the risk of side effects." Both alcohol and ibuprofen are independently hard on the stomach, so combining them is additive: MedlinePlus notes the risk of stomach bleeding is higher for people who "drink large amounts of alcohol while taking ibuprofen," and the FDA over-the-counter Drug Facts label lists having "3 or more alcoholic drinks every day" among the factors that raise the chance of severe stomach bleeding.
Keep alcohol moderate and stick to the lowest effective ibuprofen dose for the shortest time (do not exceed the dose on the label). Per the FDA label, the risk of stomach bleeding is higher if you are 60 or older, have had ulcers or bleeding problems, take a blood thinner or steroid, take other NSAIDs (such as aspirin or naproxen), take ibuprofen longer than directed, or have 3 or more alcoholic drinks every day. Stop and contact a doctor right away if you notice stomach pain, heartburn, vomit that is bloody or looks like coffee grounds, or stools that are bloody, black, or tarry. People with liver or kidney problems, stomach ulcers, or who drink heavily should check with a GP or pharmacist before combining the two, and should not take ibuprofen unless told it is safe.
This is general reference, not medical advice, and not a guarantee of safety. Interactions depend on your doses, health conditions, and other medicines. Always confirm with your pharmacist or doctor before combining products, and follow the dosing on each label.