from diffusers import AutoPipelineForText2Image
import torch

device = "cuda" if torch.cuda.is_available() else "cpu"

pipeline = AutoPipelineForText2Image.from_pretrained('black-forest-labs/FLUX.1-dev', torch_dtype=torch.bfloat16).to(device)
pipeline.load_lora_weights('Keltezaa/female-masturbation-fingering', weight_name='Mast.safetensors')
image = pipeline('Nude 26yo woman masturbating, leaning back on a bed, one hand under her butt, one hand near her chest. Spread legs. Midriff and thighs. Her crotch is exposed.').images[0]

For more details, including weighting, merging and fusing LoRAs, check the documentation on loading LoRAs in diffusers