Just when you thought you had the baby burrito mastered, the swaddle unravels — once and for all.Good-bye, wrap. Hello, sleep sack.Make the transition to swaddle-free sleeping as easy as Sunday morning (before kids) with the latest from Aden + Anais. The beloved swaddle maker fashioned its famous cotton muslin into crib sheets.Just like the company’s all-purpose blankets, the muslin bedding gets softer every time it’s washed. Elastic edging makes for a secure fit over the mattress, and a wide weave allows air to circulate, helping regulate baby’s temperature and keep him safe.The sheets come in soft, solid colors (gray, pink, blue) and delicate patterns (owls, stars, dogs) that lull even the youngest resters into a deep sleep.Just like a burrito but without the indigestion.Available online at adenandanais.com, $30-$40.Photo: Courtesy of Aden + Anais PLAYMessy Sensory ActivitiesWhat: Throw on a smock and let them get icky with hands-on activities (ages 0-3).Why: Bonus: You don’t have to clean up.When: Ongoing. Mon.-Thurs. & Sat., 10 a.m.-4:30 p.m.; Fri., 10:30 a.m.-noon, 2-5 & 6-8 p.m.Where: Boston Children’s Museum, PlaySpace Exhibit, 308 Congress St., Seaport District (617-426-6500). Adults and children, $12; babies, free.LISTENWellesley Books Story TimeWhat: Kick off the weekend with free stories and art projects.Why: Say a final farewell to winter with spring-themed crafts.When: Every Sat., 10 a.m.Where: 82 Central St., Wellesley (781-431-1160).DIVE INBlue Discoveries Family DayWhat: Learn about octopi and other creatures that swim through the New England Aquarium.Why: Don’t miss one of its oldest inhabitants, Myrtle the green sea turtle.When: Sat., 11 a.m.-3 p.m.Where: Central Wharf (617-973-5200). Adults and children 12 and up, $23; children under 12, $16; under 3, free.